Ordnance-sighting apparatus



v Jan. 29, 1924.

A. T. DAWSON ET Ag.

ORDNANCE SIGHTING. APPARATUS Filed May 15 1922 2 Sheets-Shoot l 352k "LEEQMQTFEIQfiL i'iSTEUMENTa-H Jan. 29, 1924. 1,481,859

A. 'r. DAWSON ET AL QRDNANCE S I GHTI NG APPARATUS Filed May 15. 1922 2 Sheets-Sheet 2 Witt ra tled wit-i (Rhianna-m 1 a.

Patented Jan. 29, 1924.

UNITED STATES PATENT OFFICE.

ARTHUR TREVOR DAWSON AND GEORGE THOMAS BUOKHAM, OF WESTMINSTER, LON- DON, ENGLAND, ASSIGNORS TO VICKERS LIMITED, OF WESTMINSTER, LONDON,

ENGLAND.

ORDNANCE-SIGHTING APPARATUS.

Application filed May 15,

To all whom it may concern:

Be it known that we, Sir ARTHUR TREVOR Dawson and Sir Gnonon THOMAS BUCKHAM, both subjects of the King of Great Britain,

6 and both residing at Vickers House, Broadway, lVest-minster, in the county of London, England, have invented certain new and useful Improvements in or Relating to Ordnance-Sighting Apparatus, of which the fol- 10 lowing is a specification.

This invention relates to ordnance sighting apparatus having lateral deflection gear for displacing the sight. in order to compensate for the speed of the target in a direction at right angles to the line of sight and isT rticularly althouglpnQLfiZQlllgy 1? p icable to the sighting apparatus of antiircraft ordnance.

Accorc mg to the invention we provide means whereby the lateral adjustment of the sight to compensate for drift deviation is given or corrected through the intermediary of the lateral deflection gear of the sight in such a manner that the said compensation is in accordance with the tangent elevation only for which purpose the index or setting mark appertaining to the lateral deflection dial may be automatically adjusted so that in resetting the lateral deflection gear to agree with the new position of the index or setting mark the required drift adjustment will be given. v

l/Waen the invention is used in conjunction with sighting apparatus in which the sight bracket is moved relatively to the gun by tangent elevation gear and vertical deflection gear the sight bracket may be arranged to move about an axis disposed at a small inclination to the axis of the gun trunnions as is well understood. This arrangement would give a drift allowance or deviation dependent upon the total angle of tangent elevation and vertical deflection and we therefore in carrying out our present invention in this construction of sighting apparatus provide means operated by the vertical deflection gear for correcting the deviation produced by the inclined axis of the sight bracket by an amount dependent upon the amount of the vertical deflection. When the invention is used in conjunction with sighting apparatus (whether having an independent line of sight or not) in which the tangent elevation dial is set in accord- 1922. Serial No. 561,041.

ance with tangent elevation only a cam ec centric crank or gearing carried by a part moving with this dial may be provided for efl ecting the required adjustment of the sight through the intermediary of the lateral deflection gear to compensate for drift deviation.

In order that the said invention may be clearly understood and readily carried into effect the same will now be described more fully with reference to the accompanying drawings in which- Figure l is a side elevation showing a form of the invention as applied to ordnance not having an independent line of sight.

Figure 2 is a section taken approximately on the line 22 of Figure 1.

Figure 3 is a- View similar to Figure 1 showing another form of the invention applied to ordnance not having an independent line of sight, and

Figure 4 is a side elevation showing a form of the invention applied to the sighting apparatus forming the subject of our patent application No. 561,042 filed concurrently herewith.

In Figures 1 to 3 A is the sight bracket pivoted at a to one of the gun trunnions and B is the sight carrier pivoted at b to the sight bracket. In all the figures, C is the lateral deflection dial, C the adjustable index or setting mark appertaining to the said dial, C the lateral deflection hand wheel and E the tangent elevation dial.

In the construction shown by Figures 1 and 2, the trunnion a of the sight bracket A is arranged at a small inclination to the axis of the gun t-runnions as shown in Figure 2 for imparting drift correction as is well understood and a part moving with the vertical deflection dial D has a cam groove F with which a roller 7 on one end of a link F engages. The other end of this link is pivoted at f to an arm F 2 which is pivoted co-axially with respect to the lateral deflection dial C and carries the aforesaid index or setting mark C The said cam groove is so formed that it moves the index or setting mark C to add to or subtract from the lateral deflection an amount based upon the amount of vertical deflection that has been given to the sight. In this manner when the lateral deflection gear is re-set to bring the dial graduation correspondingly to the original lateral deflect-ion opposite the index or setting mark C the drift correction that is thereby imparted to the sight will be in accordance with the tangent elevation.

In the construction shown by Figure 3 the roller 7' on the link F pivoted to the arm F engages with a cam groove E formed in a part carried by the tangent elevation dial E which is set in accordance with tangent elevation only. The said cam groove is so formed that the amount of displacement given thereby to the index or setting mark C will correspond to the drift compensation necessary at the particular angle of tangent elevation to which the dial E is adjusted so that in resetting the lateral deflection gear as above described the necessary adjustment to this gear will be effected in accordance with the tangent elevation.

In both of the above described constructions the sight, is elevated by a floating arc G having rack teeth. In Figures 1 and 2 the bracket G carrying the tangent elevation gear is attached to the gun cradle and the bracket carrying the vertical deflection gear is formed on the sight bracket A. Consequently the tangent e evation gear moves the arc G, together with the sight bracket, relatively to the gun and the vertical deflection gear moves the sight bracket relatively to the said arc. In Figure 3 on the contrary, the vertical deflection gear moves the arc G, together with the sight bracket, relatively to the gun, and the tangent elevation gear moves the sight bracket relatively to the said arc.

In the construction shown by Figure l the invention is employed in conjunction with a gun having an independent line of sight, whereas in Figure 3. as well as in Figures 1 and 2, there is no independent line of sight. Also in this construction the index or setting mark C is adjusted by an eccentric E which is driven from the shaft of the tangent elevation dial E set in accordance with tangent elevation only as described in the specification of our aforesaid concurrent patent application No. 561.042.

It is to be understood that a cam groove could be used instead of the eccentric E in Figure 4 and that an eccentric could be used instead of the cam groove E in Figures 1 to 3; also that in all the constructions shown a crank or suitable gear could be used instead of the said cam groove or eccentric.

What we claim and desire to secure by Letters Patent of the United States is 1. In an ordnance sighting apparatus comprising sight, a sight support and sight moving means the improvement which comprises in combination a lateral deflection gear for displacing the sight to compensate for the speed of the target in a direction at right angles to the line of sight, of means for imparting lateral adjustment to the sight through the intermediary of said :ateral deflection gear to effect the correct compensation for drift deviation in accordance with the angle of tangent elevation.

2. In an ordnance sighting apparatus, in combination a gun, a sight for said gun, lateral deflection gear for displacing the sight to compensate for the speed of the target in a direction at right angles to the line of sight, a bracket carrying said sight, tangent elevation gear for effecting relative elevational movements between the gun and said sight bracket, vertical deflection gear for also effecting relative elevational movements between the gun and said sight bracket, means whereby the sight is automatical'y deflected for drift deviation during all such relative elevational movements and means whereby said automatic deflection is corrected to bring it into conformity with that required for the tangent elevation movement only of the sight bracket.

3. In an ordnance sighting apparatus. in combination a gun, a sight for said gun, lateral deflection gear for displacing the sight to compensate for the speed of the target in a direction atright angles to the line of sight, a bracket carrying said sight, tangent elevation gear for effecting relative elevational movements between the gun and said sight bracket, vertical deflection gear for also effecting relative elevational movements between the gun and said sight bracket. means whereby the sight is auto matically deflected for drift deviation during all such relative elevational movements and means whereby the portion of said drift deviation deflection due to the vertical deflection movement of the sight bracket is eliminated through the intermediary of the lateral deflection gear.

4. In an ordnance sighting apparatus, in combination a gun, a sight for said gun, lateral deflection gear for displacing the sight to compensate for the speed of the target in a direction at right angles to the line of sight, a bracket carrying said sight, tangent elevation gear for effecting relative elevational movements between the gun and said sight bracket, vertical deflect ion gear for also effecting relative elevational movements between the gun and said sight aracket, means whereby the sight is auto matically deflected for drift deviation during all such relative elevational movements, an indicating device appertaining to said lateral deflection gear, and means operated by said vertical deflection gear for adjusting said indicating device in accordance with the correction required to eliminate the portion of the drift deviation deflection due to the vertical deflection movement of the sight bracket.

5. In an ordnance sighting apparatus, in

combination a gun, a. sight for said gun,

Ill)

lateral deflection gear for displacing the sight to compensate for the speed of the target in a direction at right angles to the line of sight, a bracket carrying said sight, tangent elevation gear for effecting relative elevational movements between the gun and said sight bracket, vertical deflection gear for also effecting relative elevational movements between the gun and said sight bracket, means whereby the sight is auto matically deflected for drift deviation during all such relative elevational movements, a graduated lateral deflect-ion member, an index against which the graduations are read and means operated by said vertical deflection gear for adjusting said index in accordance with the correction required to eliminate the portion of the drift deviation deflection due to the vertical deflection movement of the sight bracket.

6. In an ordnance sighting apparatus, in combination a gun, a sight for said gun, lateral deflection gear for displacing the sight to compensate for the speed of the target in a direction at right angles to the line of sight, a member moving in accordance with tangent elevation only, an element operated by said member to agree with the drift deviation compensation necessary at any particular angle of tangent elevation and means whereby said drift deviation compensation is imparted to the sight through the intermediary of the lateral deflection gear.

7. In an ordnance sighting apparatus, in combination a gun, a sight for said gun, lateral deflection gear for displacing the sight to compensate for the speed of the target in a direction at right angles to the line of sight, a member moving in accordance with tangent elevation only, an element operated by said member to agree with the drift deviation compensation necessary at any particular angle of tangent elevation, an indicating device appertaining to the lateral deflection gear and means where by said element operates upon said indicating device to displace it in accordance with the required drift deviation compensation to be given to the sight.

8. In an ordnance sighting apparatus, in combination a gun, a sight for said gun, lateral deflection gear for displacing the sight to compensate for the speed of the target in a direction at right angles to the line of sight, a member moving in accordance with tangent elevation only, an element operated by said member to agree with the drift deviation compensation necessary at any particular angle of tangent elevation,

a graduated lateral deflection member, an index against which the graduations are read and means whereby said device operates upon said index to displace it in accordance with the required drift deviation compensation to be given to the sight.

ARTHUR TREVOR DAWSON. GEORGE THOMAS BUCKHAM. 

